Select periodicity

You can select the dimension of the lattice:

Select periodicity "Bulk"

The colored lines that you see in the drawing area are the lattice vectors. The first lattice vector is colored red, the second green, and the third blue. Because a number of neighboring cells are displayed you see a collection of cubes. You can enable/disable this:

Use the 'Periodic>Show Periodic' menu command from the 'View' menu to toggle the periodic display

Without the periodic display you see the more clearly the three lattice vectors.