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