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