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