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