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