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