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)(11,16)(12,15)(13,17)(14,19)(18,23)(20,22)(21,24)(25,26)(27,30)(28,37)(29,39)(31,34)(32,35)(33,40)(36,38)(2,5)(6,7)(12,20)(15,22)(18,24)(21,23)(25,27)(26,28)(29,31)(30,35)(32,37)(33,34)(36,40)(38,39) involution — undirected(1,3,4,8)(2,6,5,7)(9,11)(10,14)(12,18)(13,19)(15,21)(16,17)(20,24)(22,23)(25,28,32,30)(26,27,35,37)(29,38,40,34)(31,33,36,39)(1,2)(3,6)(4,5)(7,8)(9,12)(10,15)(11,18)(13,20)(14,21)(16,23)(17,22)(19,24)(25,29)(26,33)(27,36)(28,38)(30,34)(31,37)(32,40)(35,39) involution — undirected(9,11)(10,16)(12,18)(13,19)(14,17)(15,23)(20,24)(21,22)(25,30,32,28)(26,27,35,37)(29,34,40,38)(31,33,36,39)(9,10)(11,14)(12,15)(13,17)(16,19)(18,21)(20,22)(23,24)(25,31,32,36)(26,34,35,38)(27,29,37,40)(28,33,30,39)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.