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