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