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