I agree, dont just look for graduate scheme, but also don't overlook it.
I am a mature student (graduated at 35) and managed to get a graduate role with 30 others. There are 2 other mature graduates at 29 and 30yo. I would say it is harder for over 30s to get a graduate role but its not impossible ( I am out of 6 mature students in my class with me being the only to get a graduate role - I am the 3rd oldest). It took me 7 months and several graduate interviews, 4 graduate interviews got into 2nd stage with 2 of them offered me a role, and the rest stopped as soon as I mentioned I have a family and they asked questions that are in a breach of employment law.
The objectives of the graduate roles in the company is crucial so you need to find the right company. Most companies just want highly skilled cheap labour. The company I work for more interested in your potential as they expect graduates to be the future leaders in the company. So your maturity will be a big advantage in managing workload, communicating with other etc.
From my experience, discrimination doesnt come from the company as we are protected by HR and employment law, but its more from your peers. I tend to be excluded by other graduates from activities, or discussion even when ur there! Cynical comments about nearly 40 and still in a grad level, and 'i will at least be a manager at that age' kind of comments, unfair comments when you do or don't do so well relating to age (from colleagues or grad peers). Some colleagues also treat you differently when they know your age as they see you as a threat more than 'a kid'. Eventhough in all fairness my knowledge of the business is the same as a new starter at what ever age they are as I have never worked in this environment before (very technical).
But don't be discourage, keep going, you got this far. Use your age and life experience as an advantage. The big boss in my company says, 'mature students have better work ethics and sense of responsibility than the younger ones because we don't work for the weekends' which I found to be true.
Good luck for all the mature students out there!