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)(14,20)(15,25)(17,19)(21,28)(22,27)(23,24) involution — undirected(1,2,3,4)(13,14,19,24,18,23,17,20)(15,22,16,27,25,28,26,21)(6,9)(10,12)(13,15)(14,21)(16,17)(18,25)(19,26)(20,22)(23,27)(24,28) involution — undirected(13,16,18,26)(14,22,23,28)(15,17,25,19)(20,27,24,21)(5,7,8,11)(6,10,9,12)(13,17,18,19)(14,20,23,24)(15,16,25,26)(21,22,27,28)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.