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