It depends on how fast it is. If it's fast, you can't conduct all five or seven beats. A little slower, where it's possible to conduct them, you still might not want to. In these cases, you typically conduct 5 in a 2 pattern, with one beat being 50% longer than the other. In 7, you similarly use a 3 pattern with one beat being 50% longer than the other two.
For slower speeds where you do want to indicate five or seven beats in each measure, you typically conduct a subdivided 2 or 3 pattern, just as 6/4 can be thought of as a two pattern with each beat subdivided in three, or 3/2, when conducted "in 6" typically uses a 3 pattern with each beat subdivided in two.
Thus the 5 pattern becomes down-in-out-out-up for 2+3 and down-in-in-out-up for 3+2. Similarly, the 7 pattern is down-in-in-out-out-(more)out-up, down-in-out-out-out-(more)out-up, or down-in-out-out-(more)out-out-up.
Thanks to Chris Strickland for some visual aids:
The "subdivided upbeat" patterns (b and c in the image) are standard, but I did not mention them because I find them awkward and misleading. They result in a large upward motion that doesn't serve as the preparation for a downbeat, and they leave the baton in too high a position to be able to give an appropriate preparation for the downbeat.