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