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