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