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