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