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