The card is in the supported list at nvidia site:http://www.nvidia.com/object/linux_display_ia32_173.14.25.html
GeForce 5 FX series:
FX 5700LE, FX 5600, FX 5600 Ultra, FX 5100, FX 5200 Ultra, PCX 5900, FX 5600XT, FX 5700 Ultra, FX 5950 Ultra, FX 5700, FX 5500, FX 5700VE, FX 5900 Ultra, PCX 5300, PCX 5750, FX 5900XT, FX 5900, FX 5800, FX 5200, FX 5800 Ultra, FX 5200LE, FX 5900ZT
Download the 173.14.25 driver. Give it execution permissions:
chmod +x NVIDIA-Linux-x86-173.14.25-pkg1.run
Be sure you have kernel sources installed, if you dont check the kernels directory from the repository.
Switch to the text user interface running as root init 2. Then login as root, go to the folder where you downloaded the driver and execute the installer with ./NVIDIA-Linux-x86-173.14.25-pkg1.run
Follow the instructions, they are pretty simple.
After install finish, run init 4 and that should be all.
Post back if you find any problems.