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