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