I've been out of town and just seeing this...the Capitol has been undergoing renovation for some time, but it is really starting to look nice even though the scaffolding is around and they are now putting new copper on the dome. I work across the street and think it is still worth a stop since it is near I-70 so not much out of your way. If you are here on a Sunday for sure and (I THINK) evenings, parking is free even though there are meters. They have even progressed to the point of working on the landscaping during this past month so again (and only my opinion) it is worth a stop.
Since you will be right across the street, be sure and stop at 1st Presbyterian Church to see the Tiffany Windows! Even if the church is not open, you can still see the beauty of them from the outside :)
Topeka High is just a block or two to the west of the Capitol and is also worth a quick stop to see since it was the first million dollar high school built west of the Mississippi and is also a beautiful landmark!
Then as you get back on I-70 to head west out of Topeka and if it around time to eat a meal, just take the Wanamaker exit since most of our chain hotels and restaurants are on that street. If you have further questions, please feel free to send me a personal message...I am not on TA everyday but will try to remember to check often and am glad to help!
If you are going to be in Wichita, the Museum area (near downtown) has so much to see and do, and there are several hotels in that area I've stayed in on business trips so can also help if you haven't yet booked the hotels in either city. Actually I've also stayed in Hutch if you decide to stay there.
The stop in Abilene is wonderful since the Eisenhower Museum is also worth the trip! I would suggest spending the night in Hays since my coworker was just there a month or two ago and said the Sleep Inn was very nice (also said the Best Western looked good).
Victoria is just east of Hays, and you can stop for a short visit to see the Cathedral of the Plains, and it's a fund German community!
That's probably more that you wanted to read, but please let me know if I can help you with more info :)