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