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