hi,
i think all the suggestions given were extremely good. I would just like to add that you need to be absolutely clear about the objective in presenting this data to the senior management - are they looking primarily at the stats of the attrition in the organization or are they already aware of the same and focussing more on the retention strategies.
This would enable you to make the presentation answering directly to what they are looking for. For instance, if it is the former case, then you should perhaps focus more on number crunching - generate slides as per the attrition percentage level wise, performers wise (how many high performers have left the orc vis-a-vis the non-performers, group wise, etc.) but if it is the latter, then this information can be used only as an introduction to the presentation (maybe a slide to show what they are there for) but the focus should be on what are the necessary steps that you would be taking on retaining the employees.
Usually, the retention strategies that are thought about are actually a resultant of the exit interviews taken - i am sure that in your exit interview, you do ask the employee about his reason for leaving - you could introduce the topic of retention strategies on the basis of the number of people who have mentioned say, a higher compensation as a reason for leaving, or issues with seniors (if that is a major concern).
You could perhaps, delve into the analysis as to what can be done about the pay scales or hierarchy in the organization (depending upon what the exit employees have answered).
However, from my personal experience, i think only suggestions should be given in the presentation. You should leave the actual decision making to the management and EXPRESS that too in the presentation. If you keep repeating your point, then it might help in them registering what you think but it also might be taken as infringment on their actual authority.
Hope my tips help you ! good luck !
Regards