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