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