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