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