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