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