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