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