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)(13,14,18,21,19,24,17,23)(15,20,26,27,16,22,25,28)(5,7)(6,9)(8,12)(10,11)(13,15)(14,20)(16,19)(17,25)(18,26)(21,27)(22,24)(23,28) involution — undirected(1,2,3,4)(14,21)(17,18)(20,27)(22,28)(23,24)(25,26)(7,12)(9,11)(13,16,19,15)(14,22,24,20)(17,26,18,25)(21,28,23,27)(6,10)(9,11)(15,16)(20,22)(25,26)(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.