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