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