Well, a dragon could use scimitars that had an enchantment from MotW, so let's move on.
The dragon in question would get 4 BAB attacks, one speed attack (we'll assume that you can't get one from both, for the obvious reasons), plus 3 off-hand BAB attacks.
Then the dragon would get the bite, 2 wings, the tail slap.
So I guess you'd get 12 attacks.
You'd have: scimitar +74/+74/+69/+64/+59 and off hand scimitar +74/+69/+64, bite +64, 2 wings +64, tail slap +64
Damage: scimitar 1d6+24, off hand scimitar 1d6+15, bite 4d8+17, wings 2d8+8, tail slap 4d6+25
If you assume the dragon has the proper sized scimitars, then the scimitar damage shoots up to something like 4d8+24 for his collosal scimitars.
He could power attack for +20 to damage (at -20 to hit). I'd assume that he also buffed with Righteous might... quite the feat for a collosal being.
That would increase the damage to (not including power atk)... scimitar 8d6+26, bite 8d6+19, wings 4d6+9, tail slap 4d8+28.
Add divine favour or prayer for another +6 to hit and damage.
The kicker to all this would be to cast iron body. Final damage (with power atk)
scimitar 8d6+55, off hand scimitar 8d6 + 44, bite 8d6+48, wings 4d6+37, tail slap 4d8+59.
Of course, there could be more.