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