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