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)(27,31)(28,35)(29,37)(30,33)(32,34)(36,39)(38,40)(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)(25,27,30,29)(26,31,33,37)(28,34,36,38)(32,39,40,35)(3,8)(5,7)(25,28,30,36)(26,32,33,40)(27,34,29,38)(31,39,37,35)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.