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