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