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)(15,21)(16,18)(17,25)(19,24)(20,22)(23,27)(26,28)(1,2,4,3)(5,6)(7,10)(8,9)(11,12)(14,18)(19,26)(20,25)(21,27)(1,3,4,2)(13,15,22,28,16,23,17,24)(14,19,25,27,18,26,20,21)(6,9)(10,12)(13,14)(15,19)(16,18)(17,20)(21,24)(22,25)(23,26)(27,28) involution — undirected(5,7,8,11)(6,10,9,12)(14,18)(15,23)(20,25)(24,28)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.