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