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