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