What is the difference between a positive and negative electron orbital?
There are no such things as positive or negative electron orbitals. The number in the subscript is $m$, known as magnetic quantum number and running from $−\ell$ to $\ell$. It doesn't tell you much about the atom. It is a property of the orbital, not of the atom. Every atom has all these orbitals at once (some of them occupied and some empty); also, there are versions of each for different $n$.

In a free atom, all orbitals with the same $n,\;\ell$ and different $m$ have the same energy, so this number does not mean much for an orbital either (at least unless you put the atom in a magnetic field).

Moreover, the pictures are fake anyway. Orbitals which are the true eigenfunctions of $m$ (that is, correspond to specific $m$) are complex-valued and thus can't be properly represented in a plot. As for the orbitals featured on this diagram (and all over the textbooks), these are the linear combinations of complex orbitals for different $m$, hence each of them does not correspond to any particular $m$. It's not that they are wrong per se (absolutely not!), it's just that you can't point at them and tell which is $p_1$ and which is $p_{-1}$.