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