Air Carrier Captain reported receiving a 'Cabin Altitude Warning' during cruise which prompted the flight crew to executed an expedited descent to 9000 ft. and complete the Cabin Altitude checklist. Flight crew then requested special handling to a diversion airport where a safe landing was completed.

Narrative

At FL380 we received a CABIN ALTITUDE WARNING". We immediately donned oxygen masks and established crew communications. The First Officer (FO) contacted ATC and I started an emergency descent. The FO ran the CABIN ALTITUDE checklist. As we were descending; the FO stated that the cabin altitude was 9000 ft. The CABIN ALTITUDE warning light remained on for about 8-10 minutes and then extinguished. I don't know exactly at what altitude this occurred; but I believe it was in the low teens. After the FO completed the CABIN ALTITUDE checklist; requested special handling and coordinated a divert into ZZZ. We accomplished all normal checklists and an uneventful ILS XXC approach and landing. We taxied into parking without incident. CABIN ALTITUDE 2 was enunciated on the status page. My ears popped as we received the warning and I felt slightly light headed as I was donning the oxygen mask. It went away shortly thereafter. Overall; I think we did a good job. I could have included the experienced jumpseater in the resolution of the event sooner. Once he was involved; some of the load was lifted from the FO and I. The other jumpseater was a new hire and this was his first flight on the 757."