A short weekend trip - all I can think of is traffic until you get past Magic Mountain in Valencia. Wuksachi Lodge in the Park would be nice, if you can get accommodations and it is a little pricey.
The 16 miles of Hwy 198 from the Ash Mountain entrance to Giant Forest has 130 curves and 12 switchbacks - definitely not a speedway. You may want to drive to Three Rivers and stay the night and spend a full day up in Sequoia. At the end of the day, take another road out and find lodging - perhaps in Fresno or Visalia on the way home. It's a short weekend that you only have, that may be the way to go.
Some of the parking lots near the Morro Rock and the trees may be crowded, and may take up some of your time.
Last year we stayed at Holiday Inn Express in Three Rivers. At 9 a.m. we were picked up by Sequoia Tours and spent a full day in Sequoia. It was so interesting, with several stops, and lunch at the Wuksachi Lodge (on your own). In the evening, my husband and I had dinner along the Kaweah River at the Gateway Restaurant.
The tour is $83. adult.
www.AmericanParkNetwork.com and do a search for Sequoia. It has a lot of information on sights, etc.