I'll draw something up for you later (have to work now) but to start with, forget the contactor you linked to as it is (a) AC coil and you are using DC and (b) as mentioned above you need some interlock to avoid both contactors/relays from coming on at the same time causing a dead short( not feeding back power to the inverter)
If you have a 24v dc motor with a full load rating of 10A and you gear it down to such a low rpm, then I doubt very much that it will ever get anywhere near the full load current when running.
However, DC motors tend to create a large amount of sparking at the contactor contacts during startup and sometimes shutdown so best to stay with the higher current contactor of at least 10A.
Finally, your diagram is quite ok.........gets the message through and that's the important part.
I've seen many drawn with sophisticated programs that are not worth a crumpet.