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