One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,6,4,5,7,8)(9,10)(11,19)(12,16)(13,25,27,17)(14,18)(15,22,29,26)(20,33)(21,32)(23,36,38,30)(24,31)(28,35,39,37)(34,40)(9,11)(10,15,18,29)(12,20)(13,26)(14,21)(16,28,31,39)(17,32,25,19)(22,27)(23,37)(24,34)(30,40,36,33)(35,38)(2,5)(6,8)(9,12,14,24)(10,16,18,31)(11,20,21,34)(13,23,27,38)(15,28,29,39)(17,30,25,36)(19,33,32,40)(22,35,26,37)(11,21)(15,29)(19,32)(20,34)(22,26)(28,39)(33,40)(35,37) 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.