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