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