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