You could utilize PowerApps and a powerapps webpart to do this to some degree or a full page app as I do. If you are trying to do a directory I would recommend it for sure since you can build a gallery from AD users and then create a SharePoint list to house your external users to also add to that same gallery.
I posted an example directory I did that you could tweak to add in the manual ones from another datasource and collect it to the same collection:
https://techcommunity.microsoft.com/t5/SharePoint/employee-directory/m-p/379781#M28204Anyway, that only works for a full directory, if you're trying to just put a who to contact type snippet, then I don't know of anything out of the box, might check out github SharePoint spfx webparts for something that might fit the bill there, or you could very well try to make powerapps work with a web part that looks good, problem is sometimes sizing it just right to fit dynamically in the section of a page.