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