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