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