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