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