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