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