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