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