Diapers are barely noticeable under clothes.
Even for toddlers who wear diapers and you know they are wearing a diaper it can be hard to tell they have a diaper on.
For example even my 2 year old son who wears diapers it can be hard to see that he has a diaper on under his pants or shorts.
Even though I know he's wearing a diaper I cannot really tell he has one on underneath his pants or shorts.
However if it gets wet and starts to sag some then I can tell.
But most people probably don't even realize he has a diaper on unless his shirt rides up.
The same is true for adults as even for an adult it can be hard for others to know they are wearing a diaper.
Most people are not even looking for a diaper anyway.
So if you need to wear diapers then you should do so.
Just wear some good fitting shorts, pants etc and wear a long enough shirt so they don't ride up and show the waistband but even then most people are too busy with their own business to notice or care you have a diaper on.