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