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