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