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)(11,16)(12,14)(13,17)(15,19)(18,23)(20,21)(22,24)(25,26)(27,33)(28,37)(29,39)(30,32)(31,36)(34,35)(38,40)(1,3,5,8)(2,6,7,4)(9,11)(10,15)(12,16)(13,18)(14,19)(17,22)(20,23)(21,24)(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)(17,20)(18,24)(22,23)(26,32)(29,37)(31,33)(35,40) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,12,14,10)(11,16,19,15)(13,20,21,17)(18,23,24,22)(25,28)(26,29)(27,34)(30,39)(31,35)(32,37)(33,40)(36,38)(1,3)(2,4)(5,8)(6,7)(9,11)(10,16)(12,15)(13,18)(14,19)(17,23)(20,22)(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)(10,17)(11,18)(12,20)(14,21)(15,22)(16,23)(19,24)(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.