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