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