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