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