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