Is the color of the bricks different than the color of the words?
Yes, the words are black and the bricks are white.
    src        edge_attr  dst
0     1   to the left of   11
1     1   to the left of    5
2     1               on    8
3     2   to the left of    6
4     2  to the right of    5
5     3   to the left of    6
6     4               on    8
7     4   to the left of    5
8     5  to the right of    4
9     5   to the left of    2
10    5  to the right of    1
11    6               on    8
12    6  to the right of    3
13    6  to the right of    2
14    7               on    2
15    9               on    2
16   10               on    1
17   10   to the left of   11
18   11  to the right of   10
19   11               on    8
20   11  to the right of    1