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