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