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