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