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