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