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