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