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