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