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