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