As noted on the Wikipedia page, they were looking at a wavelength of 1420 MHz, since this is a common emission line, and the extraterrestrials would presumably use something common like that. Most of the light in the Universe, however, is from the Cosmic Microwave Background Radiation , so I figure that they might send a signal using some characteristic CMB wavelength. Being a blackbody with a temperature of about 2.7 Kelvin, the CMB is a broad-band signal, but as noted on the Wikipedia CMB page, it has characteristic wavelengths of between 1 and 2 mm, or equivalently, between about 150 and 300 GHz. This puts it firmly in the wavelength range of the Planck/HFI instrument.
Here is a Planck 217 GHz map of the full sky (on the left) and a zoom on the region with the Wow! Signal on the right:
Nothing leaps out at us (so to speak), so let's try to zoom into the specific regions of interest. The right ascension (J2000) of the event is either 19h25m31s ± 10s or 19h28m22s ± 10s and declination = -26°57' ± 20'. This gives Galactic coordinates of (l, b) = (11.6641769256, -18.9165090814) or (l, b) = (11.9093554501 -19.5079303722).
Here is the same image as the one above, but with these regions highlighted:
It doesn't look like anything to me. Too bad...