Find My Past will only list your grandfather's birth if he was a British national. These records originate with the British Consulate in Egypt.
If he was not British, you have a couple of different options.
Compulsory civil registration in Egypt began relatively late. Until then, different nationalities in Egypt kept their own records of births, marriages and deaths within the community. So if your grandfather was deemed an Italian or French national, say, it is best to contact the archives of their respective consulates.
You may also wish to try contacting the Jewish Community in Egypt to ask for information, although I have found it very difficult to get a reply from them.
(For Catholic records, it's also worth trying church records such as St. Catherine's Alexandria)
Generally speaking, getting information out of Egypt is very painstaking although I have had some success with three different Egpytian families (one Jewish, including the name Levy) of late.
Please let me know if you need any help. I am a family historian specialising in Jewish family history.
Best wishes, Naomi Leonwww.researchroots.co.uk