It's all technique my friend... well not all but a lot of it.
Look at any of the players who launch it and they'll have strong quad and buttocks!!
But without doing any weights etc
1. Which part of your foot are you kicking the ball with?
For power you want to hit it with your laces (the top of your foot) and have your foot pointing down inline with your shin.
there are 2 ways to hit it like this, if you look at CR7 he is very upright and swings his leg through like a pendulum. I prefer to be leaning to my left slightly and have a bit more of a sweeping motion. (all though you are prob more likely to slip doing it this way - so carefull if on concrete)
Plant your standing foot pull the heel of your kicking as far back & close to your arse as poss and then swing through with as much power catching the ball as you leg full extends.
Try and also get your bodyweight moving through as well keep your hands up for balance and smash that bad boy!!
Keep your weight foward and chest level with the ball unless you want it to clear the wall and the ajoining streets
THat been said its useless been able to hit a ball hard if you can't put it where you want...
Assume that your technique is perfect, and now the whole thing is dependent on muscles.