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