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