It sounds like a scene from the Miss America Pageant, except the drawing cards will not be shapely, smiling beauties.

Instead, they will be three-piece-suit politicians -- governors from a host of states and the District of Columbia's Mayor Marion Barry -- all on show at a Jan. 18 governors' reception, the first invitation event of President-elect Ronald Reagan's inauguration.

While an expected 5,000 spectators, each grasping a red $10 ticket, gather in a heavily decorated 280-foot-long ballroom at the Sheraton Washington Hotel, military bands from the Navy, Marines and Coast Guard will play "dignified, yet rousing tunes," according to inaugural officials. Suddenly, a round of trumpets will sound and a deep-voiced announcer will call out the name of the first governor or other honored official expected to attend.

As his name is called, the official will slowly descend a plush, red-carpeted staircase and weave through the applauding crowd to an eight-by-eight-foot carpeted booth raised about six inches above the ballroom floor. The walls of the booth will be royal blue pleated fabric.

"Each governor will hold his own court [in the booths]," explains reception spokesman Henry Maggenti. Above each booth a state, territory or commonwealth seal will be displayed.

About every 20 minutes, trumpeters will play tunes like "Fanfare for the Common Man," Maggenti says. That will be a signal to the roomful of ticketholders that their time in the ballroom is running out. Within minutes, another 5,000 persons holding $10 white tickets will be ushered in to wander among the booths and greet the governor of their choice. Again, the trumpets will sound and still another 5,000 persons with blue $10 tickets will enter.

Sometime during the three-hour reception, Vice President-elect George Bush is expected to be a special, royal blue booth.

"Since President-elect Reagan emphasized the return of government to the states in his campaign, we feel it is appropriate that the reception honoring the governors of the states and territories be the first official invitation event of the innaugural celebration," explained Fred Dixon, the reception's chairman.

While a few tickets to the event may be sold to the public, most will go to diplomats and officials from the states whose governors are being feted, says Dixon, who planned a similar reception for President Nixon in 1969.

Thirty-three governors plan to attend so far, Dixon said, including Virginia Gov. John Dalton and his wife, Eddy, and Maryland Gov. Harry Hughes and his wife, Patricia. Mayor Barry will stand in his booth alone, a press aide said.

"We believe this reception will truly be one of the major highlights of the 1981 inauguration," said Dixon.