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