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