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