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