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