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