1.44 draw diagrams representing the positions of the atoms in diamond and graphite

Covalent Structures

These are two images of a covalent structure. 

Diamond has a 3D lattice with 4 carbon-carbon bonds

Graphite has a 3D lattice with 3 carbon-carbon bonds

On  the left is diamond and on the right is graphite.

NB - Graphite has only got 3 covalent bonds and 1 delocalised electron. That's why it can conduct electricity. Also the bonds in between the layers are weak and so the layers of graphene can slide over each other and be used as a lubricant.