"The Group," that small but social pride of Californians, flew into town last week to help their friend, President Ronald Reagan, celebrate his 70th birthday. And the celebrating didn't stop after Friday Night's White House "surprise" spectacular.

Before their dancing heels had a chane to cool, they were off again, to a Saturday lunch at the Fairfax Hotel hosted by Kansas City socialite and GOP fund-raiser Carol Price and husband, Charles -- and then to a dinner at the Watergate's Jean Louis restaurant given by two of the inaugural impresarios, Charles and Mary Jane Wick.

"After this weekend, we may almost be partied out -- almost," said one of the crowd.

At the Jean Louis, there were truffles, and tales, and toasts to triumph.

"If it weren't for the efforts of this group," the president joked to the crowd of 48 during his toast, "I'd be making this speech before the Chamber of Commerce."

"These people have been with the president through thick and thin," said a more recent addition to the crowd. "They knew him when."

James Stewart serenaded his table with "Ragtime Cowboy Joe," and according to one guest announced that he will soon be going on the road with an abridged version of the play "Harvey."

House Minority Leader Robert Mitchel (R-Ill.) got up and launched into "Old Man River," and then "Send In the Clowns." "He looked a little sheepish at first. I don't think he was expecting to be asked to sing," said one guest.

The crowd included cabinet member William French Smith and his wife, Jean, CIA Director William Casey, Alfred and Betsy Bloomingdale, inaugural co-chairman Robert Gray, and Walter and Leonore Annenberg and Virginia and Holmes Tuttle.

During the president's toast, Nancy Reagan, who wore a dove-gray crepe dress adorned with a silvery stripe across the bodice, rose to stand beside the president. But only the president spoke. "He said he was going to give a toast that only he and the first lady would be able to drink to," said one guest. "And then he toasted us! It was very informal, and the president was very funny."

Chef Jean Louis had placed jelly beans in an antique Oriental bowl, which stood near the entrance to the restaurant.In addition to the jelly beans, the eight-course meal included foie gras on toast, scallops with truffle butter and salmon. That was followed by veal and California asparagus, and ravioli stuffed with wild mushrooms.

"It took five hours to do the ravioli," said Jean Louis. "We made 150 of them -- by hand." And then , salad, and pastry and black currant sherbet with raspberries. The wine and the champagne were French.

"I'm going on a grapefruit diet for the next week," said one guest later.

On the top of the menu at each place setting was an inscription, addressed to "Our Man of Destiny and his First Lady," which read, in part, "California Here We . . . Came -- Tonight Let Us Enjoy Our Great Beginning."

The presdent and first lady left the party an hour later than scheduled, which delighted both the hosts and the small crowd of late-night wanderers who had gathered near the exit.

"Happy Birthday!" cried an elderly woman, leaning over the staircase railing, her arm outstretched. Reagan looked up and smiled, and appeared to wink, or maybe be was just squinting. It didn't matter.

"He winked at me," cried the woman as the president had disappeared into the restaurant, which had been cleared for the occasion. "He winked at me!" she repeated to her companion. "Calm down," commanded her friend, "before you make yourself sick. Or me."

"It's been a busy four days," said Charles Thornton, of Litton Industries, standing in the lobby of the Fairfax as the Price luncheon got underway. "We've been in and out of meetings, talking over appointments. One of the meetings started at 7 a.m.!"

He was asked what the women in the group had been up to these past days. "The women?" he said. "Well, I don't know exactly. I suppose they talked a lot. And bought dresses . . . and talked about the dresses."

Washingtonian C. Wyatt Dickerson, who'd had a big party during the inauguration, said his wife, Nancy, was in Arizona, at tennis camp. He sipped his drink, greeted guest Jerome Zipkin, then peered out the hotel door.

"My Rolls Royce," he said "has conked out on the driveway." He pointed to a stalled mass of shining gray metal cooling on the Fairfax's circular drive. "How inconvenient."

Dickerson hadn't been to the White House birthday party Friday night. "They didn't invite anyone from Washington, which was probably a good idea, don't you think?" But Dickerson said he'd heard from others that they'd spotted a memento from the Dickerson party sitting on the president's desk. "It was one of the few things on there. It's sort of a truncated trapezoid. I'm so pleased," he said, although another guest at the birthday party could not recall seeing it.

The 45 guests nibbled on Maryland crab cakes, salad and strawberries Romanoff. "It's been frantic," said Nancy Reagan's decorator, Ted Graber. "I'm alive, but just barely." Others in the crowd: Sen. Mark Hatfield (R-Ore.), James Stewart, who came with his wife, Gloria, and actress Irene Dunne; Betty and William Wilson, and Earle and Maron Jorgensen.

Inside the bar Attorney General Smith raised his glass in a toast to Holmes Tuttle for being one of the three who first talked Reagan into running for governor.

"Let us be gay," said Walter Annenberg to his wife as they stood in the lobby.

"I think we've been gay for quite some time," said his wife, removing her fur coat. "I think it's time for us to come back down to earth."

"Oh no," cried Carol Price. "Not yet!!