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