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