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