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