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