# a rough solution here

from scipy import signal
y,sr=librosa.load("your audio  file.wav")
widths = np.arange(1, 128) # scales for morlet wavelet 
cwtmatr = signal.cwt(y, signal.morlet, widths) # the second parameter is where we are selecting a mother wavelet and the widths defines how many alterations on the mother wavelet needs to be performed to analyse the signal from different frequency resolutions, you should read more about them. 
plt.imshow(abs(cwtmatr), extent=[-1, 1, 31, 1],cmap='plasma', aspect='auto',
           vmax=abs(cwtmatr).max(),
           vmin=-abs(cwtmatr).min()) # finally we plot the scalogram
plt.show()

pywavelets库更适合于小波分析任务，然后您可以使用matplotlib来绘制尺度图。