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