As far as I know there is no ready-made module that could show a map of locations - most stores has a single location where items are shipped from.
You need someone to code this for you as a custom module. You can hire our team (
https://www.x-cart.com/custom-development.html), or find a good third-party developer (
https://forum.x-cart.com/forumdisplay.php?f=23).