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