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