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