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