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