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