This is a modification of driverguide download #67820. I had someone who was running 95 and needed the drivers to fit on a single floppy.
It might work with 98 but I think 98 already has native driver support for most S3's.
Create a folder named something like S3 and unzip the file there. Then open the display adapter in device manager and choose to install or upgrade (whichever is appropriate) the existing driver. When it asks where to look for the drivers browse to the S3 folder.