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