  We construct a polynomial-time algorithm that given a graph $X$ with $4p$
vertices ($p$ is prime), finds (if any) a Cayley representation of $X$ over the
group $C_2\times C_2\times C_p$. This result, together with the known similar
result for circulant graphs, shows that recognising and testing isomorphism of
Cayley graphs over an abelian group of order $4p$ can be done in polynomial
time.
