you can use plt.matshow() instead of plt.imshow() or you can use seaborn module's heatmap (see documentation) to plot the confusion matrix
import seaborn as sn
import pandas as pd
import matplotlib.pyplot as plt
array = [[33,2,0,0,0,0,0,0,0,1,3],
[3,31,0,0,0,0,0,0,0,0,0],
[0,4,41,0,0,0,0,0,0,0,1],
[0,1,0,30,0,6,0,0,0,0,1],
[0,0,0,0,38,10,0,0,0,0,0],
[0,0,0,3,1,39,0,0,0,0,4],
[0,2,2,0,4,1,31,0,0,0,2],
[0,1,0,0,0,0,0,36,0,2,0],
[0,0,0,0,0,0,1,5,37,5,1],
[3,0,0,0,0,0,0,0,0,39,0],
[0,0,0,0,0,0,0,0,0,0,38]]
df_cm = pd.DataFrame(array, index = [i for i in "ABCDEFGHIJK"],
columns = [i for i in "ABCDEFGHIJK"])
plt.figure(figsize = (10,7))
sn.heatmap(df_cm, annot=True)