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