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