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