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