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