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