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