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