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