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