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