Not diagonally, but:
1. Add a rectangle from the Drawing toolbar.
2. Right click, choose Add Text, enter DRAFT and click away.
3. Right click and choose Format Autoshape.
4. Set your font size etc on the Font tab.
5. On the Colours and Lines tab choose Fill colour No fill, Line colour No line.
6. Set other formatting as desired (eg Alignment).
7. Click OK