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