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