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