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