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