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