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