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