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