The GW150914 blackhole merger event recorded by aLIGO, represented in a wavelet (morlet base) spectrogram. This spectrogram was based on the audio file released with the original announcment.
The data from the second detection, GW151226, is another beast entirely in that the signal is very much buried in the noise.
Raw data:
Wavelet Spectrogram: 
The LIGO Open Science Center makes these data available, along with signal processing tutorials.
Now to see how the professionals do it:
I used MATLAB’s wavelet toolbox for the visualisations, aided by this example
The Scinder 