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