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