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)(11,14)(12,16)(13,17)(15,18)(19,22)(20,21)(23,24)(25,26,31,33)(27,34,29,32)(28,30,35,40)(36,39,38,37)(1,2)(3,5)(4,6)(7,8)(9,11)(10,14)(12,19)(13,18)(15,17)(16,22)(20,23)(21,24)(25,27,31,29)(26,32,33,34)(28,36,35,38)(30,37,40,39)(11,18)(14,15)(19,24)(22,23)(26,33)(27,29)(30,40)(36,38) involution — undirected(9,10)(11,14)(12,20)(13,17)(15,18)(16,21)(19,23)(22,24)(25,28)(26,30)(27,36)(29,38)(31,35)(32,37)(33,40)(34,39) involution — undirected(1,3,4,7)(2,5,6,8)(9,11)(10,15)(12,19)(13,18)(14,17)(16,23)(20,22)(21,24)(25,29,31,27)(26,34,33,32)(28,38,35,36)(30,39,40,37)(9,12)(10,16)(11,19)(13,21)(14,22)(15,23)(17,20)(18,24)(25,30)(26,35)(27,37)(28,33)(29,39)(31,40)(32,38)(34,36) 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.