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