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