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