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