That is, two vertices are adjacent in the Schläfli graph if and only if the corresponding pair of lines are skew.
It plays an important role in the structure theory for claw-free graphs by Chudnovsky & Seymour (2005).
Correspondingly, in the Schläfli graph, each edge uv belongs uniquely to a subgraph in the form of a Cartesian product of complete graphs K6
The Schläfli graph has a total of 36 subgraphs of this form, one of which consists of the zero-one vectors in the eight-dimensional representation described above.
The proof relies on the classification of finite simple groups.