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