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