There are 3 damage patterns:
Type 1, shallow (Missiles and Plasma)
Type 2, medium (Railgun, particle beam)
Type 3, deep (Laser)
Type 1 is the most well known and forms a cone wider than it is deep. It works out as follows (for strength 1-9)
12357
468
9
Type 2 appears to be a narrow cone as deep as it is wide.
Type 3 is deeper than it is wide, appear as nearly vertical stab at low damages.
I'm not confident enough on the exact pattern to post any diagrams on 2 or 3.