What to do when you're not confident your advisor will be able to write you a strong LoR?
The best practical approach is to try to make it as easy as possible for your "hands-off" advisor to write the best letter about you. Even if they delegate the task to someone else, it will be helpful for whoever is writing to have all the relevant information about you. I recommend at least preparing the following: 


A summary of your research accomplishments. If you worked in teams, highlight what you personally added.
A summary of your non-research contributions to the lab. This includes students that you mentored, any responsibilities you took on, other kinds of service to the department or university, and times when you helped others with their research.
A few of your strengths and a specific example for each. 


Whether your recommender uses this information is up to them. Having it  can only increase the odds that their letter is more thorough, specific, and helpful to your application. 

Finally, having an advisor like yours is obviously not ideal, but it is also far from uncommon. I assume that their mentees in the past have gone on to successfully find jobs, postdoctoral appointments, etc. So maybe your advisor cares more about writing recommendations than you might guess based on their advising style. After all, an advisor does have some interest in the success of their students as well.