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