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