You want $P(a|d)$ where $a$ means active, $d$ means diabetic. Then Baye's rule gives $$ P(a|d)=\frac{P(d|a)p(a)}{P(d)} $$ We know $P(d)=\frac{202}{5990}$. $P(a)=1/4$ and $P(d|a)$ we need to figure out. But $$ P(d)=1/4P(d|a)+3/4p(d|s)=1/4P(d|a)+3/4*5P(d|a) $$ Can you finish from here?