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