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