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