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