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