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)(27,37)(28,32)(29,36)(30,34)(31,35)(33,39)(38,40)(9,11,13,19)(10,14,16,17)(12,18,21,24)(15,22,20,23)(25,27)(26,32)(28,31)(29,38)(30,39)(33,40)(34,36)(35,37)(1,3,5,4)(2,6,7,8)(25,28,39,30,31,27,29,38)(26,32,33,34,35,37,36,40)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,29,31,39)(26,33,35,36)(27,38,28,30)(32,40,37,34)(1,4,5,3)(2,6,7,8)(11,19)(14,17)(18,24)(22,23)(25,30,29,28,31,38,39,27)(26,34,36,32,35,40,33,37)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.