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