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)(11,19)(12,20)(13,18)(14,16)(15,21)(17,23)(22,24)(25,26,30,32)(27,31,34,28)(29,37,40,33)(35,36,38,39)(1,2)(3,5)(4,6)(7,8)(9,11,14,21)(10,15,16,19)(12,18,23,22)(13,20,24,17)(25,27)(26,31)(28,32)(29,38)(30,34)(33,36)(35,40)(37,39)(4,8)(6,7)(10,16)(13,24)(15,19)(17,20)(26,32)(27,34)(33,37)(35,38) involution — undirected(2,3)(6,7)(9,12)(10,17)(11,18)(13,15)(14,23)(16,20)(19,24)(21,22)(25,28,30,31)(26,27,32,34)(29,39,40,36)(33,38,37,35)(1,3,5,2)(4,7,8,6)(9,11)(10,15)(12,22)(13,20)(14,21)(16,19)(17,24)(18,23)(25,29,30,40)(26,33,32,37)(27,35,34,38)(28,36,31,39)(1,4,5,8)(2,6,3,7)(9,13,14,24)(10,18,16,22)(11,20,21,17)(12,15,23,19)(25,27)(26,31)(28,32)(29,35)(30,34)(33,39)(36,37)(38,40)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.