Hey, hope you are doing fine
Out of the box you can't have a temperature graph, what you can do is see onboard system events and alert based on temperature.
What servers do you use? this is important because management system differs from manufacturer to manufacturer.
If you have vROPs you can do something like you requesting, but for that you need to add a management pack (for example a HPE-OneView) and configure it to recollect hardware metrics
I'm not sure if you can do it on sexigraf SexiGraf
Hope this works