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