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