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