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