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