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