Can I use a vacuum to clean out the dust of my xbox one S Fan?

I recommend not to, you can damage the fan, it would be better use some compressed air instead.

I wouldn't use a vacuum cleaner. You could damage the fan.

Im just looking to keep the dust from stopping the xbox, so yeah the dust.

Please review this page for details on how best to clean and maintain your console and discs. It will provide the best information to make sure it
has clear ventilation for operation and maintain it for the longest life.

This article from Windows Central also has plenty of good tips on cleaning your console safely.

Is there something in particular that you're looking to safeguard against? Pet hair? General dust and dirt?

It is not recommended to use a vacuum or electronic appliance to clean another electronic. Reasons vary. A vacuum for example can cause damage to your Xbox through transmitting static electricity that can harm the components inside. Compressed air from a
compressor often spits tiny droplets of water out with the stream of air it is blowing out.

The best method of cleaning is a clean dry cloth for most cases or having your Xbox serviced if the fan is failing or overheating is occurring