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