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