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