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