This arpeggio calls for a specific fingering to make it work which is also typical for economy picking. Its as the title says diminished and I will shoe you a cool way to work it into a traditional Major scale

As you can see in the picking part of the video I play a picking stroke on each and every note, so no pull off´s or hammer on´s on the spots where I play more than one note which is typical for Sweep Picking. But in Economy or Speed Picking you pick every note and arrange the fretting hand to make use of all the picking strokes. The fingering gets changed around when you move into the third inversion of the Dimished arpeggios. in order to make the economy picking work and making use of all the fingers so I can easier speed it up. Because re use of fingers can in many situations keep the speed down in my opinion.  
High E string is little finger and index finger. B string is long finger, G string is little and index finger 
Same fingering as the first inversion
Third inversion starts on the G string with little and index finger, long finger on the and ring and index on the A string
Same fingering as third inversion
If you play a seven string you can continue the same fingering as on third and fourth inversion

In this little phrase I kick the lick of from the top of the first position of the Major scale and end it one semitone higher than the fifth position of the Major scale. So as soon as I end there I immediately move into the fifth position and continue my improvising from there. This way you get a little bit of Harmonic Minor fifth position which is dominant flat nine and flat sixth which is a cool way to spice up your Major scale. Good luck !