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