The way the mini-toggles are wired (sort of) will link the humbucker rails with the single coil in parallel when in the middle position. Up and down will give you just the single coil or just the rails, respectively. Is this the layout you want? The other option is to have the rails and single coil linked in series for an extra high power triple bucker in the middle position, not hard to change if that's your preference.
Every On/On/On mini-toggle I've used has the contact sequence like the the
image on this page . But, the Warman site sells switches which apparently have this sequence (which matches the layout in your sketch):
Attachment 12990
I'm not sure where you're getting your mini-toggles from, so your layout may need to change. To make your layout work with either type you just need to extend each of the red, blue and yellow wires across the two lugs at their level. So, the yellow and blue would both extend to the lug to their left, the red would extend to the lug to its right.
Your volumes' connections appear to be reversed and need to have the red and yellow lugs swapped. So, red wire to the right hand lug (as it's drawn) and the yellow wire (ground) to the left lug. Also, you don't appear to have drawn in the caps for the tone controls. They would just replace the yellow link to the back the tone pots.