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