
Alexis M. answered 10/20/19
WordPress Expert Specializing in Web Design WITHOUT Code
You could use icons to represent each business/business category. Here's a link to a site that offers free icons: https://www.flaticon.com/
You can also separate each business/business category into different sections of the page that have different background colors, textures, shapes, dividers, etc.
And I recommend still adding some type of pictures, even if they are stock photos that could represent the business/business category. You could even include the logo next each business, etc.
Let me know if this is helpful.