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