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