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