I think the illustration is a certain year of a CB400T but there are no others in the manual.
The manual shows tapered side down. My fork spring is more straight and doesn't look tapered like in the picture but I've seen that type of spring on internet. However If I look closely the last coil is actually a little bit smaller so I guess it should be down. That means tight side up.
My springs was put in the other way with the tight side down and that's how most people on other Hondas has their spring from what I've seen but it doesn't mean it's correct for my model.
Edit: the tight side should be up according to Haynes manual and they had a non tapered spring just like mine.