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