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