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