(Disclaimer, not a master priest myself, just repeating a lot of the stuff I found on this site.)
Well, you seem to be using a lot of PoH.
General consensus now is using Chakra Sanctuary with renew/coh on cooldown spams. You cast renew about 74 times, generally this should be higher. Cast more renews to lower cooldown on CoH and cast that on cooldown where at least 3+ people are damaged. I would almost suggest dropping your multistrike enchants for Haste. Haste will lower the GCD for renew and also cause it to tick more in the same amount of time.
Drop the Fade glyph for CoH or Binding Heal glyph. the BH glyph allows BH to heal target, yourself, and an additional third target for increased mana cost. The CoH heals a 6th target for increased mana cost.
Power Infusion is nice to have if you remember to use it. Twist of Fate has been working very well for me as well, as I usually have renew on most players, if any ever drops, I get the buff.
Lastly, do you use Divine Hymn at all? I couldnt seem to find that spell on your log. This is comparably weak when viewed side by side with other big CD's, but timing this right will save the raid and put up big numbers. 3 min cooldown, you can at the very least use it two times on most boss fights, you should be able to fit in 3 comfortably for majorityof bosses.
So my general rotation is keep renew up on tanks always, start putting it on all char before big attacks, put them on damaged char.
PoM on cooldown, generally I put them on tanks or myself.
I'll use CoH on cooldown if more than 3 targets need a heal.
Blanket more renews to lower the CoH cooldown.
If big damage is coming, I'll channel DH.
If someone is dangerously low on health, I'll use a Flash Heal or Binding Heal once or twice for Serendipity, then cast a normal Heal or PoH if there is large party damage.
Guardian Spirit on tanks not when they are just low on health, but when they will need large amounts of healing.
Mind Bender and any other mana regen on CD.
Edit: Lastly, Holy priests are reactive healers. We need damage for our numbers to go up. It will be difficult to beat Disc or classes with quicker heals.