I need the diagram for the serpentine belt on a 2005 Suzuki forenza

SOURCE: i need a diagram of a 2004 suzuki forenza

That's easy, there are some pulleys with ridges to grip the underside of the belt, and some are smooth for the top side of the belt.
I can only assume your belt broke and fell off so you couldn't see how it was on prior. But either way you have limited length, and the last place you would be routing the belt is the tensioner, which you should have located first, so you can have a wrench handy to fit it.

Here's what you have:
Top left= alternator (small ridged)
top right = power steering (large ridged)
Bottom right = AC compressor (large ridged)
Bottom middle = Crank Pulley (large ridged)
In middle next to Power steering = Tensioner (small shiny smooth)

Remove the air cleaner housing (two bolts)
Start on left top side and loop belt (clockwise) across the alternator to the power steering down to AC (also clockwise from right to left) then over to crank pulley (from bottom clockwise around to top of pulley) to tensioner (smooth, belt is backwards on it) which will go back up to the alternator.

At the top middle there should be a sensor protruding from the timing cover that the belt passes under as it connects between the alternator and the power steering. And you won't easily be able to fit anything besides a box-end wrench on the tensioner, so you may need some kind of extension on the wrench to get good torque on it without hurting yourself.

SOURCE: I need a serpentine belt

Draw your on before taking the old one off. I allways do I never look for diagrams its easy.