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