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