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