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