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