How do I politely decline this potential job offer without closing the door to future employment?

I am graduating this semester with a degree in a fairly specialized field. At an industry conference recently a former professor of mine, who now works for one of the biggest companies in the area. introduced me to a department head and recommended me for a job I didn’t even realize was open. I spoke to the manager who said she had heard about me, asked when I would be available, said she had planned to have a temp in the position until then, and asked me to send a resume and keep in touch. I spoke to another friend in the industry and it turns out that before the introduction, the hiring manager had sent her an email inquiring about my availability and qualifications for the job.

I know I am incredibly fortunate to already have folks interested in hiring me and I am really excited that this professor thought enough of me to recommend me for the job, but I am not sure the position is the right fit. It is a great position but I was planning to start grad school and maybe take some time off before starting a full on job hunt.

The question is, how can I politely say I am not interested without burning bridges for future employment with this company. It is definitely a place I would like the opportunity to apply and be considered at some point, just not right now.