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