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)(11,12)(13,21)(14,17)(15,19)(16,22)(18,23)(20,24)(27,30)(32,34)(35,37)(39,40) involution — undirected(2,5)(6,7)(9,11)(10,15)(12,17)(13,18)(14,19)(16,23)(20,21)(22,24)(25,26,31,28)(27,32,30,34)(29,36,38,33)(35,40,37,39)(1,2)(3,6)(4,5)(7,8)(9,10,14,17)(11,15,19,12)(13,21,22,16)(18,20,24,23)(25,27,31,30)(26,32,28,34)(29,35,38,37)(33,39,36,40)(1,3,4,8)(2,6,5,7)(9,10)(11,15)(12,19)(13,16)(14,17)(18,23)(20,24)(21,22)(25,28,31,26)(27,34,30,32)(29,36,38,33)(35,40,37,39)(9,12,14,15)(10,11,17,19)(13,20,22,23)(16,18,21,24)(25,29)(26,33)(27,35)(28,36)(30,37)(31,38)(32,39)(34,40)(9,13,14,22)(10,16,17,21)(11,18,19,24)(12,20,15,23)(25,30,31,27)(26,34,28,32)(29,37,38,35)(33,40,36,39)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.