Short answer to your question: No. Photostory is Windows only.
Slightly longer answer: it might work if you were prepared to install Bootcamp on your mac and then, in that partition, also install a full version of Windows 10, and then install PS. However, there can be no guarantees of success!
To add to @emmrecs comment . . . . it might work . . . .
I would add that the iMAC, if you have not got it yet, must be an Intel based model.
You also have to consider the future as there will be no more Intel based models produced as Apple change over to their own processors which creates another issue of its own.