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