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