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)(13,14,19,20,18,15,16,22)(17,21,26,27,25,23,24,28)(6,9)(7,11)(13,15,19,22,18,14,16,20)(17,23,26,28,25,21,24,27)(1,2,3,4)(13,16,18,19)(14,20,15,22)(17,24,25,26)(21,27,23,28)(5,7,8,11)(6,10,9,12)(13,17)(14,21)(15,23)(16,24)(18,25)(19,26)(20,27)(22,28)(6,9)(10,12)(17,25)(21,23)(24,26)(27,28) 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.