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