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