I checked my Catskill books, and I did not find a good reference that I could recommend. On the inside cover of Alf Evers' book The Catskills there are three profiles with the mountains identified. But these are from vistas within the Catskills, and would not help much with a view from Shawangunks. If you have photos that you can post, the Catskill/Gunk hikers among us should be able to help with the identification.
The discussion of mountains listed below is from right/east to left/west. From many locations in the Gunks you will see the entire "Devil's Path" mountains on the far northeast (right). From Skytop these will appear directly above the Mohonk Mt House. Typically you can see Plattekill, Overlook, Indian Head (somewhat scalloped appearance), Twin (compact with two summits), Sugarloaf (rounded), Plateau (long profile that slopes gently to the left/west), Hunter (with SW Hunter on the left), Westkill (a long ridge), North Dome, then several smaller mountains somewhat difficult to differentiate.
Then Ashokan High Point (a somewhat elongated pyramid with a lower knob on the right/east, and if you have good eyes you will notice a deep glacial gash far down its right side which is Wagon wheel Gap. To the left of Ashokan High Point is a long ridge (Little Rocky).
Then 3 or 4 high bumps - which are in a wide cirque so one is often hidden from a Gunks view. In the northern Gunks you may see Wittenberg, Cornell, Balsam Cap (with Friday hidden behind). In the southern Gunks you are more likely to see Balsam Cap, Friday, Cornell (with Wittenberg hidden behind).
You may see a lower peak (Rocky) then Slide Mt, the highest point on the horizon which slopes gently to the west/left. Lone may appear in front of Slide -- it appears as an elongated pyramid if you do see it. Then two mountains: Table (a short flat plateau) and Peekamoose (in front) which will appear as a bump somewhere along the flat profile of Table depending on your location. Left of that from the southern Gunks you may see Doubletop, Graham, and Balsam Lake Mt.