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