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