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