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