One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,8)(9,10)(11,12)(13,14,16,18)(15,19,20,17)(22,26)(24,31)(27,32)(30,35)(2,4)(6,10)(7,11)(22,26)(23,29)(28,33)(30,35) involution — undirected(1,2)(3,4)(5,6,9,10)(7,8,11,12)(21,22)(23,27)(24,28)(25,26)(29,32)(30,34)(31,33)(35,36)(5,7)(6,8)(9,11)(10,12)(13,15,16,20)(14,17,18,19)(21,23)(22,27)(24,30)(25,29)(26,32)(28,34)(31,35)(33,36)(5,8)(6,11)(7,10)(9,12)(21,24,25,31)(22,28,26,33)(23,30,29,35)(27,34,32,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.