I agree with the Museum of Tolerance, but on a Saturday you may need reservations in advance. Same with the Getty Museum.

Griffith Park, LA Zoo and the Gene Autry Museum are all together and would fill the time nicely too. Dinner would round off the time. Maybe down at the Marina. I like the Cheesecake Factory, but I am sure may other suggestions would be equally good or better.

Los Angeles also has an operating winery downtown (just east), the San Antonio Winery (737 Lamar St). A nice historic place for lunch. Follow up with a trip to Olvera Street for some of the Mexican history of the city. The flower mart, a sandwitch at Phillipe's or at the Produce Market. Maybe a walk thru of the train station.

Hollywood is also a trip by itself. Greyline or a car. Drive up Sunset and down Hollywood. Endless places to stop and tour. Chinese theatre, wax museum...