This would take a bit of coding to do – there are a couple ways to go about it:
1. Creating a variable in the category.php file that will insert a header image based on the category ID (probably the easiest option).
2. Duplicating the category.php file and renaming it to something appropriate (category-notes.php, for example), editing the code to insert the image where you want it, then calling that php file based on the category ID within the loop.
3. I won’t get into this one, as it’s more difficult than 1 or 2 – I’m just letting you know there’s a 3rd option.
I’m pretty sure that Swift team wouldn’t be able to give you specifics on how to do this – if you’re not comfortable with coding of this nature, your best bet would be to hire someone to do it for you…