on what part?
ghost on summoner spell? for gabcloser, and why then not flash? cuz if you flash 1 stun is enough to get the gab bigger again. Ghost&Wither combination will give you a guaranteed kill in what lane whatsoever
Runes?
the attackspeed for his passive, to get it more lifesteal. the movementspeed for to hit wither
masteries?
nasus is lategame champ, and will be focussed alot, with the deep masteries in defensive i can sustain alot more damage then if you take reduced slow/tenacity + you will already have enough tenacity with ancient golem
items?
all items will help nasus alot, and with a complete build you are tanky enough & deal enough damage with gauntlet and you will have 40% reduced CD. Maybee you dont need the Omen, but i like that item alot when you play a agressive jungler that will go for the back lines of the enemy team.
abilities?
after you leveld your E up to 3, you dont need more damage to kill camps, so i max Q after that for more damage, and less CD to pump it more up
why i dont level wither the 2nd? because lvl1 wither has enough slow & recuded attckspd to succeed a gank, and when teamfight will start, you'll have more points in wither
the only thing that is considerable for change is the mark runes, you could change that maybee in Armor Pen.
but since this rune page is the most common page i use as jungler i will leave it as it is :)
every jungler should have that page (attckspd, armor, mr/level, movementspeed)
but thats just my P.O.V. :p