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