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