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