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