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