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