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