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