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