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