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