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