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)(23,26)(24,27)(25,33)(28,32)(29,34)(30,36)(31,35) involution — undirected(1,2,4,3)(5,7,9,6)(8,13,16,11)(10,14,18,12)(15,17,20,19)(21,23)(22,26)(24,31)(25,29)(27,35)(28,36)(30,32)(33,34)(5,8,10,17,9,16,18,19)(6,11,12,15,7,13,14,20)(22,27)(23,29,31,30)(26,34,35,36)(28,33)(1,3,4,2)(6,7)(11,13)(12,14)(15,20)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.