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