One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(13,14)(15,17)(16,18)(19,20)(21,22)(23,31)(24,27)(25,29)(26,30)(28,34)(32,35)(33,36) involution — undirected(2,4)(5,6,8,10)(7,11,12,9)(13,15,16,19)(14,17,18,20)(22,27)(24,25)(28,35)(29,30)(31,36)(33,34)(5,7,8,12)(6,9,10,11)(21,23)(22,28)(24,34)(25,33)(26,32)(27,35)(29,31)(30,36)(14,18)(17,20)(23,32)(28,36)(31,35)(33,34) involution — undirectedA 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.