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