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