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