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)(16,17)(18,22)(19,23)(20,24)(25,26,30,34)(27,35,36,31)(28,32,38,40)(29,37,39,33)(2,5)(3,8)(10,15)(12,16)(13,22)(19,24)(27,36)(29,39)(31,35)(33,37) involution — undirected(1,3)(2,6)(4,5)(7,8)(10,15)(11,17)(18,21)(19,24)(25,27)(26,31)(28,37)(29,32)(30,36)(33,38)(34,35)(39,40) involution — undirected(1,4,7,6)(2,3,5,8)(9,11)(10,16)(12,15)(13,19)(14,17)(18,23)(20,21)(22,24)(25,28)(26,32)(27,33)(29,35)(30,38)(31,39)(34,40)(36,37)(1,5,7,2)(3,4,8,6)(9,12,14,16)(10,17,15,11)(13,20,22,23)(18,24,21,19)(25,27)(26,31)(28,37)(29,32)(30,36)(33,38)(34,35)(39,40)(1,6,7,4)(2,8,5,3)(9,13,14,22)(10,18,15,21)(11,19,17,24)(12,20,16,23)(25,29)(26,33)(27,32)(28,35)(30,39)(31,38)(34,37)(36,40)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.