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