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