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