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