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