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