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