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