Do you want to use a different icon for each location, or do you need different icons per category?
For instance,
Location A: Petes grocery carries Apples. you want an Apple Icon.
Location B: Sally’s market carries organic non gmo, and you want that to show a tree icon
Location C: Jim’s shop carries beauty supplies . You want an icon that reflects beauty supplies
Location D: is one mega store but it carries all of Pete’s , Jims and Sally’s products all in one location and you want all three of those icons to show up.
If that scenario you need Power Add-on with the category and store manager settings
Or if you merely want Location A to show a map marker that is a Blue pin
Location B to be a Red pin, etc you can do that on an individual location selection.
Depending on how you want to display:
You need the Power Add-on which has category taxonomy and can have different icons and map markers and multiple icons per location appear in the results table with either a default map markers or a category map marker. Please read the documentation about the various options.
If you want to customize layouts , use CSS, change appearances of results, searches, and/or maps that is the Experience Add-on
If you want all of the above and more, review the features in the Premier package