I would start by trying off the boat slips in Marina Cove. There is normally someone out there with pretty good crowds at times. Most everyone uses some type of small jig, but it sounds like a few anglers have been catching them with large 3" baits on 1/8 and 1/4 ounce jig heads. Early morning and afternoon seem to be the best times. It is free (state park vehicle permit required) and operates on a first come, first serve basis.
Other places to try this time of year are off the Cawker City causeway near the bridge, near the mouth of Oak Creek, and Osage Cove.