Maybe this cente near you may be of interest:-
Thai Elephants Center for Conservation - TECC
Address: GCQ2+GQ8, Mu Si, Pak Chong District, Nakhon Ratchasima 30130, Thailand
Hours:
Open ⋅ Closes 5 PM
Phone: +66 44 297 406
I have only visited Khao Yai National Park to see elephants in the wild. I have never visited the above Center.
It is shown on Google Maps, so may be make a visit before your friends arrive. Enjoy.