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)(25,26)(27,31)(28,34)(29,33)(30,32)(35,37)(36,40)(38,39)(3,7)(6,8)(9,11)(10,14)(12,19)(13,17)(15,22)(16,24)(18,20)(21,23)(26,27)(29,37)(32,34)(36,38) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,15)(11,17)(16,23)(18,19)(25,27,31,26)(28,34,30,32)(29,35,37,33)(36,40,38,39)(9,11)(10,14)(12,19)(13,17)(15,22)(16,24)(18,20)(21,23)(25,28,31,30)(26,32,27,34)(29,36,37,38)(33,39,35,40)(1,3,4,7)(2,6,5,8)(9,12,13,20)(10,16,15,23)(11,18,17,19)(14,21,22,24)(25,29,31,37)(26,33,27,35)(28,36,30,38)(32,39,34,40)(1,2)(3,6)(4,5)(7,8)(9,10)(11,14)(12,16)(13,15)(17,22)(18,21)(19,24)(20,23)(25,30,31,28)(26,34,27,32)(29,38,37,36)(33,40,35,39)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.