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