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