Christofides, Hladky, and Mathe (http://arxiv.org/abs/1008.2193) proved using the Regularity Method the case when the vertex-transitive graph is sufficiently dense.
Hamiltonicity of dence Cayley graphs
Christofides, Hladky, and Mathe (http://arxiv.org/abs/1008.2193) proved using the Regularity Method the case when the vertex-transitive graph is sufficiently dense.