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