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