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