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