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