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