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