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