Visualizing items frequently purchased together
I think what you probably want is a discrete version of a heat map.  For example, see below.  The red colors indicate the most commonly purchased together, while green cells are never purchased together.
 

This is actually fairly easy to put together with Pandas DataFrames and matplotlib.



import numpy as np
from pandas import DataFrame
import matplotlib
matplotlib.use('agg') # Write figure to disk instead of displaying (for Windows Subsystem for Linux)
import matplotlib.pyplot as plt

####
# Get data into a data frame
####
data = [
  ['Banana', 'Water', 'Rice'],
  ['Rice', 'Water'],
  ['Bread', 'Banana', 'Juice'],
]

# Convert the input into a 2D dictionary
freqMap = {}
for line in data:
  for item in line:
    if not item in freqMap:
      freqMap[item] = {}

    for other_item in line:
      if not other_item in freqMap:
        freqMap[other_item] = {}

      freqMap[item][other_item] = freqMap[item].get(other_item, 0) + 1
      freqMap[other_item][item] = freqMap[other_item].get(item, 0) + 1

df = DataFrame(freqMap).T.fillna(0)
print (df)

#####
# Create the plot
#####
plt.pcolormesh(df, edgecolors='black')
plt.yticks(np.arange(0.5, len(df.index), 1), df.index)
plt.xticks(np.arange(0.5, len(df.columns), 1), df.columns)
plt.savefig('plot.png')