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