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)(23,24)(25,30)(31,32)(33,36) involution — undirected(1,2)(3,4)(5,7,10,8)(6,11,12,13)(9,15,17,16)(14,18,19,20)(21,22,27,29)(23,30,24,25)(26,34,35,28)(31,33,32,36)(6,12)(11,13)(14,19)(18,20)(21,23,27,24)(22,25,29,30)(26,31,35,32)(28,33,34,36)(5,6)(7,11)(8,13)(9,14)(10,12)(15,18)(16,20)(17,19)(21,24,27,23)(22,25,29,30)(26,32,35,31)(28,33,34,36)(5,8,10,7)(6,13,12,11)(9,16,17,15)(14,20,19,18)(21,25)(22,23)(24,29)(26,33)(27,30)(28,31)(32,34)(35,36)(5,9,10,17)(6,14,12,19)(7,15,8,16)(11,18,13,20)(21,26,27,35)(22,28,29,34)(23,31,24,32)(25,33,30,36)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.