Jose, after this question has been online for a while and no expert answered it, let me try to provide some hints. I am not so sure what it is you are after. My intuition is that you want to know how to design diagrams efficiently.

Anyway, first of all it may be important to note that the distinction between sensation and perception is hard to make and therefore somewhat outdated. The original idea was that the senses provide raw data like smells, sounds, colours, the feeling of being touched at a point on the body etc. These (meaningless) raw data were called sensations. From sorting, combining, tracking, and classifying the sensations we would gain perceptions, i.e. the knowledge that there are objects occupying certain places or moving around in our environment and having certain forms and colours. However, what may seem to be raw data is actually already filtered and processed in the sense organs so that normally there is no point in distinguishing sensations and perceptions. It is better to talk about perceptions on different levels of processing.

As to attention, that is a kind of selection amongst all perceptions, which makes the ones picked out available for conscious inspection. Attention can either be automatically drawn to perceived events or objects or object parts based on certain features that give them "saliency", or we can voluntarily pay attention to something.

What you perhaps want to know is how to give saliency to the right part of a diagram. I recommend to look into the work of Edward Tufte, for instance his book "The visual display of quantitative information" for a start. Of course, there is much more literature.

There is a continuum between sensation and attention. How you mix it up determines the kind of perception you have (e.g. observation vs. recognition). I worked out a theory based on quantum physics that extrapolates to a metaphysical description of how we operate. You can find it at primalword.com