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