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