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