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