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