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