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