A FEAST for the eyes, the Nativity Scene of Los Heraldos del Evangelio (Heralds of the New Testament), is a 25-minute presentation of small figures in dioramas that move with rising and fading lights, all depicting the Christmas story. Here and on the facing page: an angel announces the birth of Christ, the innkeeper refuses a room to Mary and Joseph, a scene at the last Supper, Jesus is baptized by John the Baptist, villagers whirl around a shepherd playing a flute, and more. The Heralds are a community of lay Roman Catholics who follow the same vows of chastity, poverty and obedience that members of holy orders do (without being priests or nuns). They offer this charming portal to the community free of charge. The presentations are from 2-7 p.m. daily through Jan. 14 (including Dec. 25 and Jan. 1), in a white house 200 meters west and 75 meters south of the main entrance to Club La Guaria in Moravia. For more information, call 235-5410.