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