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