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