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