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