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