After enlarging the photo the key is in the lower left. The woman with the sheep is Mary(?) Robinson, Dale Carnegie is standing in the door, Sarah Caldwell is on the poster; Homer Croy is smoking a cigar in the upper left, Mary Graham is in the upper right window.
The muralist is Kelly Poling from Chilicothe who has murals there.
This article notes the murals are paid for by the Maryville Citizens for Community Action led by Alice Hersh are at Maryville Florists 214 North Main (Forsyth House), Pagliai’s Pizza, 611 South Main (NWMSU), Jock’s Notch (college/high school mascots) and the mural by the courthouse (on the H&R Building). I’m not sure if they are the same artist but this one mentions NWMSU 1978 grad Bob Walkenhorst.