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