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