The Day of Pentecost ends the Easter Season – it is the culmination of the Great Fifty Days of the Easter season.
Monday May 28 in fact is Monday in the 8th Ordinary Week. The 7th Ordinary Week began February 19. Then we had Lent followed by Easter. We pick up where we left off before Lent. IMO suggestions to use the collect for the Day of Pentecost on the days following should be ignored as it completely undermines the renewal of the Easter Season as fifty days concluding with the feast of the Day of Pentecost.
If you need a collect during this week, use the one appointed for the 8th Ordinary Week.
In with the comments, please also remember to feel free to add links and suggestions for hymns, prayers, etc. for the Day of Pentecost.