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