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