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