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