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