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