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