This is a reference to so-called 正しく努力する才能 ("talent to make a correct effort"). そういう事 refers to what he just said (努力は創意工夫だ。ただやればいいってもんじゃない).
If there is a distinction between "talented" and "no talent", it probably amounts to such a fact.
(Free translation) If there is something called a talent, that's about understanding how to make an effort effectively.
So the guy is saying that 私だって努力してる is not an excuse because improper 努力 is meaningless. The guy is also implying a right effort comes with a good result.
EDIT: 才能に有無がある is not a typo, and this に is just an (abstract) location marker used with ある/いる/etc. A very literal translation is "If there is (a distinction between) presence and absence in talent".