One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,6)(7,8,13,18)(9,19,23,29)(10,24,26,32)(11,17,12,16)(14,22,30,21)(15,27,31,25)(20,34,36,28)(33,37,38,35)(7,9,12,22,13,23,11,21)(8,14,17,29,18,30,16,19)(10,20,27,37,26,36,25,35)(15,28,32,38,31,34,24,33)(7,10)(8,15)(9,20)(11,25)(12,27)(13,26)(14,28)(16,24)(17,32)(18,31)(19,33)(21,35)(22,37)(23,36)(29,38)(30,34) involution — undirected(4,6) involution — undirectedA 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.