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