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