The plane has one problem in itself: the engines. The proportions to the wing seem off.
The body is angular as well, but still has flowing transitions to the wings.
Maybe try the same with the engines. And make the top fin more solid and flowing into it as well.
Oh and the cannons look like they could hit the front fins, which look strange anyway, best remove those fins entirely.
That would make a fine plane, but unfortunatelly it still won't be our starchaser as described in the wiki. I also noted that the saracen as it is based on the blackbird is rather unsuited for dogfighting. (but thats a different discussion:
http://ufoai.ninex.info/forum/index.php?topic=3161.0) There may be a need for another interceptor, that could be this former design.
The Starchaser however need a very different design.
First of all it needs antimatter engines, yours still look like jet engines.
The body has to be something between the dragon and the stingray. It needs a definitiv alien feel, but should still be obviously of human design..