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