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