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