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