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