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