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