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