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