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