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