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