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