I think the key thing about telling a story is thinking about the skills you used and developed during your work experience and explain why that led to you seeking a career in commercial law and how those skills can be applied to being commercial lawyer at A&O. An example would be if you worked in retail as a sales person - you had to build connections with clients understanding what they were looking for and apply your knowledge of the products to best meet their expectations. As a solicitor you need to understand the business of your client and what their goals are, so you can apply your commercial and legal knowledge to help them achieve that.
Ps I wrote something very similar to this so best not to copy and paste but I hope this gives you some insight into how you can structure your work experience and skills around being a trainee lawyer.
