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