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