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