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