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